Tube-bending machine



- 1,690,724 c. H. FREDERICK TUBE BENDING MACHINE Filed Feb. 10, 1925 Nov. 6, 1928.

6 Sheets-Sheet T M Clarvncejyfrderzck & *3

C. H. FREDERICK TUBE BENPING MACHINE Filed Feb. 10 1923 v 6 Shea Nov. 6, 1928. I 1,690,724

02" Clarerz ce fffiea erz'ck.

9% @w gm Nov..6, 192s. 1,690,724

c. H. FREDERl CK TUBE BENDING MACHINE Filed Feb. 10, 1925 6 Sheets-Sheet 3 Clarezcflf M 30% W Nov. 6, 1928. 1,690,724

C. H. FREDERICK TUBE BENDING MACHINE Fil'ed Feb, 10, 1923 s Sheets-Sheet 4 fiz 002%? Clarence Efiederzfck.

' Nov. 6, 1928. 1,690,724

. I C. H. FREDERICK TUBE BENDING MAGHIIIN'E Filed Feb. 10. 192; e Sheets-Sheet 5 mum E Z v 5? OX 39 t -Nov. 6, 1928 I v C. H. FREDERICK TUBE BENDING MACHINE 6 Sheets-Sheet 6 Filed Feb. 10, 1925 Patented Nov. 6,1928.

.UNITED" STATES p v I 1.690,?24 (PATENT OFFICE.

OLARENCE H. FREDERICK, OEKENOSHA, WISCONSIN, ASSIGNOR TOJSIMMONS COM PANY, OF KENOSHA, WISCONSIN, A CORPORATION OF DELAWARE.

TUBE -IBENDING MACHINE.

\ Application filed February 10, 1923. Serial No. 618,313.

tofore known.

Further objects of my invention are to providean improved presser member to act in conjunction with the former, to prevent scor-' ing of the tube during the bending operation, and to providea machine which is capable of efiicientlybending light gauge metal tubing. 7 The many other objects and advantagesof my invention will be better understood by reference to the following specification when considered in connection with the accompanying drawings illustrating a selected embodiment thereof .in which: J

Figure 1 is a plan view of a bending'machine incorporating my invention.

Fig. 2 is an end elevation. 95 F Fig. 3 is a section on the line 3-,-3 of i 2. Fig. 4 is a section on the line 4- 1 of Fig. 3. Fig. 5 is a section on the line 55 of Fig. 3. Fig. 6 is a detail plan view illustrating the relative positions of the former and the presser member at the completion of the bending operation. Y

Fig. 7 shows the tube after the bending operation has been completed. 1

Fig. 8 is a detail elevation of the brake mechanism for the former.

Fig. 9 is a detail elevation of theplunger operating mechanism for inserting the core- .in the tube, and i Figs. 10 and 11 are detail sectional views illustrating the construction and mode ,of operation of the flexible core.

1 Referring to the drawings, the particular machine which I have selected to illustrate the principles of my invention was designed to bend the metal tubing used in the manufacture of light-weight metal bedsteads. This tubing is generally made of light gauge steel which is much more diflicult to properly bend than heavier tubing or solid bars on account of the tendency to crinkle, buckle or otherwise become distorted. In this machine mechanism is provided to insert a flexible core into the tube pridr to the bending operation- The bending of the. tube is accomplished bya power driven oscillating former operating in conjunction with a substantially stationary presser member. Adjustable tripswith cooperating brake mechanism automatically stop the movement of the former at the ter-. 6 mination of its forward and return strokes.- The presser member is yieldingly forced against the tube by means of fluid under pressure, and preferably is provided with a soft metal operating. face for reasons which will be explained.

A base 20 or pedestal supports the substantially cup-shaped housing21 within which is stationarily supported the vertical stud shaft 22 (Fig. 4) having the former 23 journaled upon its upper extremit A worm wheel or. gear 24 is also journa ed upon the shaft 22 and a sleeve 25 is rigidly secured to the web of the worm wheel 24. The sleeve 25 is provided at its opposite ends with circular flanges or plates 26 and 27. The former 23 rests on the plate 27 and is secured thereto by means of screws 27. A top plate 30 fits within the top of the housing 21 and rests on the shoulder 30. This plate forms a support for the plate 27 and sleeve 25 thereon. All annular flange or sleeve 31 on the late 30 fits about the sleeve 25 and forms a earing therefor. Braces 32 are preferably provided. The plate 30 and sleeve 31 are split at 28 to enable the parts to be'assembled on the sleeve 25 and these parts are clamped ogether by bolts 29 passing. through opposing lugs 29'. An annular T-shaped groove 33 is formed in the upper face of the gear- 24: to receive adjustable trips or stops 34,and 35 which automatically stop the former at Y the completion of the forward and return strokes, respectively, in the manner fully described hereinafter. The former 23 is provided with a peripheral groove 0;; die cavity 36 into w'hichthe tube 37 is forced by a presser member 38. This former is actuated by a worm 39 on the shaft 40 through the medium of the worm gear 24 and the sleeve 25. This shaft 40 is in turn driven from a shaft 41'by the gears 42 and 43. The shaft 41 is mounted in suitable supports 44 and 45. Forward and reverse 'driving pulleys 46 and 47; normally free on the shaft 41, are adapted to be selectively locked thereon by the corresponding clutch members 48 and .49 respectively. These clutch members are respectively rovide'd with operating levers 50 and 51 which are fulcrumed at their in itsneutral position neither clutch is en-' ,gaged. The former is automatically stopped at each end of its stroke-by the trip fingers or stops 34 and 35, as has previously been stated. In the forward stroke of the former indicated by the arrow (Figs l and 5), the stop 34 comes into contact with the finger 60 and causes this finger to rotate the shaft 61-sufiiciently to raise the pawl 62 out of engagement with the notched'corner 63 of the block 64 secured on the rod 52, permitting the rod 52 to be drawn to the left (Fig. 3) into neutral position by the spring 65. Therod is moved into position to engage the clutch 49 by means of the hand lever 53 but before this can be done, the latch lever 66 must be swung against the action of the spring 67 sufliciently to release the lever extension 68 (Fig. 5) from the shoulder 69 on the latch lever. At the completion of thereturn stroke, the stop engages the arm 70 on the block 64 and moves the rod 52 to the right sufficiently to disengage the clutch 49. The pawl 62-now drops into the notch 63 in the block 64 and retains the rod in neutral position. When the lever 53 is moved sufiiciently to the right to engage the clutch 48 and start the forward stroke of the former, the extension 68 on this lever forces'the latch lever 66 outwardly sufficiently to permit the stop shoulder 69 thereon to snap into position behind this extension' for the purpose set forth. In order to cause the formerto stop practically instantly at the end of the return stroke in the manner described, I have provided a friction brake mechanism 71 of well-known type on the outer ,extremity of the shaft 40. This mechanism is operated by a rod 72which has its inner end connected to the rod 52 by the pin 73 extending through the slotted end 74 of the rod 72. This form of connection permits a limited relative movement ofithe rods. A shoulder7 5 on the rod 72 is in engagement w'th the corner of the block 76 on the rod 52 w 11 the rod 52 is in neutral position. Movement of the rod 52 to theleft to engage the reverse the rod 72. When the clutch 49 is thrown out at the end of the return stroke'by the automatic stop or trip 55, the movement of the rod 52 to the right'brings the block 7 6 against the shoulder 75 and applies the brake. This construction prevents the clutch 48 from being thrown into engagement by the lever 53 until the brake rod has been lifted by the lever 77 i on the lever 53 to disengage the shoulder 75. A spring 78 on the pin 73 normally retains the slotted end of the rod 72 in depressed position. At the termination of the forward or operating stroke of the former 23 suflicient braking action is provided by the presser member to be described hereinafter.

A clamp 80 of well-known type is mounted upon the former to enable the forward end of the tube 37 to be secured in the forming groove 36 during the bending operation. This clamp is operated by the lever 81. Before the bending operation is started a flexible core 82 is preferably inserted in the tube. This may be accomplished in any suitable manner. In

the present embodiment I have mounted a mechanism 83 for this purpose upon the outer end of a table or support 84. This mechanism comprises a plunger 85 having the core 82 in the form of a series of connected links joined to the end thereof, a pinion 8 6 co-acting with a rack 87 onthe plunger 85, and a hand wheel 88 for actuating the pinion. The form of'the core and the method of attachment of the links is illustrated in Figs. 10 and 11, but as this particular type is well known no description thereof is'necessary.

The presser mechanism is mounted upon a base or table 95 and is pneumatically operated. This mechanism comprises a cylinder 96, piston 97, piston rod 98, and presser member 99 on the outer end of the piston rod. The presser member is forced against the tube in the former 23 by air under pressure admitted to the cylinder 96 in rear of the piston 97 and is withdrawn therefrom when this pressure is released vby means of springs 100 provided for the purpose. The presser member 99 is preferably pivotally connected, as at 101,. to the outer end of thepiston rod 98 in order to permit a slight relative motion. This member in the present embodiment comprises a presser head 102 having a plate 103 of soft metal seated in the operative facev thereof and forming the tube contacting element of the member. This plate is very advantageous as it facilitates the movement of the tube past'the presser member and eliminates scoring. of the face .of the tube during the bending operation. Air pressure is admitted to the cylinder 96 through the pipe 104 connected to some suitable source of supply and entering the end of the cylinder in rear of the piston. A control valve 105 of suitable typeis provided in the pipe 104.- v

In the operation of the machine the end of the section of tubing to be bent is inserted in the forming groove of the former and properly clamped therein with the former in its initial-position, the presser erated to release the for the purpose.

-' er member is now released by member being withdrawn. The flexible core is now inserted by the mechanism provided Air is next admitted to the cylinder 96 to cause the presser member to be forced against the tube. The lever 77 is opbrake and the lever 53 is thrown to the right to engage the clutch 48 The worm 39 causes the former to rotate in the direction .of the arrow (Fig. 1) until the parts have reached the position indicated in Fig. 6 at which time the bending of the tube has been completed, the clutch 48 has been automatically disengaged by the stop 34 and the rod 52 has moved to'neutral. The pressthe operation of tin: valve 105 and' withdrawn by the springs 100. a

The core or mandrel is next withdrawn from the bent tube by means of the hand wheel 88 and the tube may then be removed from the former by'releasing the clamp 80. The return of the former to the starting position is accomplished by releasing the latch lever 66 from the extension of the control lever 53 and swinging the latter to its extreme left position. The engagement in this manner of the clutch 47 causes the worm 39 to rotate the former in the reverse direction or that "opposite to the forward or bending stroke.

scribed to automatically stop the rotation of the former. During the bending operation the plunger or mandrel 85 forms a support 1 out departing from having a plate of for the outer end of the tubing and advances therewith as the tube is drawn about the former. The shape of the former would depend upon the form to be given to the tube.

One of the greatest advantages of the fluid actuated presser member is its ability .to follow the curvature of the former where this curvature varies in different parts thereof. A uniform pressure is constantly maintain ed on the tube and this insures a smooth bend. This pressure is readily adjusted. The soft metal face on the presser member facilitates the passage of the tube and eliminates scoring. The distribution of the pressure over a considerable length of the tube prevents crinkling and buckling thereof during the bending operation.

The entire machine is'simple and durable in construction, easily controlled, and efficient in operation. I. am aware that the construction and arrangement of the parts may be varied withthe spirit of my invention and Ireserve the right to make such changes therein as fairly fall within the scope of the following claims.

I claim as my invention: 1. In a bending machine, a presser soft metal forming member the op erative face thereof and slidableover At the completion of the return stroke the stop 35 operates in the manner dethe face oftheblank to be bent, a forming member coactmg with said presser member, and means for movingone of said members relative to the other.

2. In a bending machine, a presser member having a plate of soft metal forming the operative face thereof and s1idable.over the face of the blank to be bent, a forming member, means for moving said pressermember into operative relation with said forming member, andmeans for moving said forming member relative to said presser membei while said members are in such relation.

'3. In a bending machine, presser mechanism includiug a cylinder, a piston within said cylinder, a piston rod connected to said piston, a resser head pivotally mounted on the outer end of said rod to permit s'el adjustment, a soft metal plate forming the operative face of said head, and means for admitting fluid under pressure to said cylindento actuate said piston. 4. In a bending machine, a forming member having portions of its operative face of different curvatures, a presser block co-acti'ng with said forming member in sliding engagement with a" to be bent, means for moving said forming member relative to said presser block, .and means for yieldingly retaining said presser member in pressing position relative to the face of said member during such movement.

5. In a bending machine, a forming member having portions of its operative face of different curvatures, a presser block co-acting blank interposed therebctween with said forming member in sliding engagement with a blank interposed therebetween to be bent, means for attaching the blank to said forming member, means for moving said forming member relative to said presser block, and means said presser block in operative position relative to said face during such movement.

6. Ina tube bending machine, a forming member, a presser block co-actingv'with said formingmember insliding engagement with for yieldingly retaining a blank interposed therebetweeir to be bent,

engageinen with a blank interposed'therebetween'to be bent, means for gnoving said block, tube clamping" forming member relative to said presser,

block, tube clamping means mounted on said forming member and movable therewith, and v means for yieldingly retaining said presser block in operative (position relative to the face of said forming member during such causing a blank to be bent to movement including a cylinder, a pistonin said cylinder, a piston rod connected to said piston and having said presser block mounted on the outer extremity thereof, and means for admitting fluid under pressure to said cylinder. f,

8. In a bending machine, the combination of a movable forming member, means for move in unison with'said forming "member, a relatively stationary presser block operable to forcesaid blankinto engagement with said member and havinga soft metal face slidably engaging said blank whereby advancing of the blank is facilitated and scoring of theblank by the presser block is prevented,

9. In a bending machine, the combination of a pivotally mounted forming member, means for turning said member on its pivot, a presser member yieldingly urged towards the periphery of said forming member so as to force a blank interposed therebetween against said periphery and havinga soft metal face engaging said blank whereby sliding of the blank across the face of said presserblock is facilitated and scoring of said blank preand means for causing the blank to vented, move 1n unison with said forming member relative to said presser block.

CLARENCE H. FREDERICK. 

